I had this problem on the 79B and had a lot of trouble diagnosing it. It had
OEM electronic ignition which was bad. I replaced it with a Crane electronic
ignition which wasn't reliable because the dizzy wobbled too much. As
suggested by several listers, I finally just took out the electronic
ignition and went with a 45D dizzy with points and haven't had a problem
since.
Monte
79B, Carmine
67B, BRG
74 1/2 Rust, parts car
----- Original Message -----
From: "Charles & Peggy Robinson" <ccrobins@ktc.com>
To: "MG Net" <mgs@autox.team.net>
Sent: Tuesday, March 04, 2003 8:41 AM
Subject: Re: No Spark
> The first thing I'd do is see if there's a spark at the coil HT wire,
> thus eliminating any prob in the dizzy cap and rotor. If there's no
> spark, I'd set my voltmeter to, say, 50 volt scale, hook it between the
> coil + side and ground, then have someone crank the engine while I
> watched the voltmeter. If the amp is triggering the coil the needle
> should bounce. If it doesn't i'd first clean every connection in the
> ignition lo-tension ckt and try again. After that it's sort of a wire
> continuity check and/or substitution method of trouble shooting.
>
> FWIW,
>
> CR
>
> Tom Bott wrote:
> > Good Day MG Docs,
> >
> > Patient: 1980 MGB LE all original with electronic ignition including
> external
> > amplifier (mounted on inner fender below coil).
> >
> > Symptoms: no spark at plugs.
> >
> > Diagnostics: I am getting 12+ volts out of the coil. But I also
> noticed that
> > when I ground the voltmeter to the engine and put the positive probe
> on both
> > positive and negative sides of coil, I am still getting 12+ volts. Is
it
> > normal to get voltage from both sides of coil? Or is something
> plugged into
> > the wrong side?
> >
> > Also, what type of volt reading should I be getting out of the
> amplifier to
> > the distributor? And does anyone know of a simple test for the
> distributor?
> >
> > As always, keep 'em runnin!
> >
> > Thanks, Tom
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